Project Summary/Abstract The Program described in the grant application will train postdoctoral (predominantly MD or MD/PhD) fellows who completed their clinical training and will be returning to the laboratory to pursue their career goal of establishing themselves as independent medical research scientists in the field of hematopoietic cell transplantation. The main applicant pool is individuals who completed Fellowships in Blood and Marrow Transplantation, or Hematology/Oncology, yet fellows from other clinical divisions or applications from PhD post-doctoral fellows whose research has direct relevance to our field and who have displayed an excellent record of pre- doctoral achievement are also encouraged to apply. Each year the training grant supports two trainees who follow a core educational curriculum, and a highly structured mentoring program that is focused on creating realistic individual development plans to enable their transition to academic faculty with careers as independently funded researchers in the field. The active growth of research into the biology of cellular and immunotherapy for treatment of cancer and other diseases, and the translation of preclinical concepts to the clinical setting demands highly trained physician scientists which justifies the unique focus of this training program.